1. Field of the Invention
The present invention relates to a multiple spindle drilling machine for wide flange beams.
2. Description of the Prior Art
When flanges of a wide flange beam are drilled, in general, this drilling operation is not conducted based on both the ends of the flange portion with respect to the widthwise direction but based on the center of the thickness direction of the web portion, namely the web center. In short, the above drilling operation should be conducted while processing the flanges upper and lower parts based on the web center. Accordingly, in the conventional drilling techniques, the web center is located to determine drilling positions, or the processing positions are determined by calculating the dimensions of the upper and lower plates based on the lower end of the flange portion.
Such conventional positioning method, however, is defective in that determination of the processing positions is very troublesome and requires much labor.